A three-dimensional computational fluid dynamics algorithm is used to study the effect of thermal and chemical nonequilibrium on slender and blunt body aerothermodynamics. Both perfect gas and reacting gas air models are used to compute the flow over a generic transatmospheric vehicle and a proposed lunar transfer vehicle. The reacting air is characterized by a translational-rotational temperature and a vibrational-electron-electronic temperature and includes eight chemical species. The effects of chemical reaction, vibrational excitation, and ionization on lift-to-drag ratio and trim angle are investigated. Results for the NASA Ames All-body Configuration show a significant difference in center of gravity location for a reacting gas flight case when compared to a perfect gas wind tunnel case at the same Mach number, Reynolds number, and angle of attack. For the same center of gravity location, the wind tunnel model trims at lower angle of attack than the full-scale flight case. Non-ionized and ionized results for a proposed lunar transfer vehicle compare well to computational results obtained from a previously validated reacting gas algorithm. Under the conditions investigated, effects of weak ionization on the heat transfer and aerodynamic coefficients were minimal.
|Original language||English (US)|
|State||Published - 1993|
|Event||AIAA 28th Thermophysics Conference, 1993 - Orlando, United States|
Duration: Jul 6 1993 → Jul 9 1993
|Other||AIAA 28th Thermophysics Conference, 1993|
|Period||7/6/93 → 7/9/93|
Bibliographical noteFunding Information:
The authors would like to thank Dr. Peter A. Gnoffo and Richard A. Thompson of the Aerothermo-dynamics Branch at NASA Langley Research Center for their many helpful discussions and assistance in grid generation. In addition, the authors would like to thank Dr. Kenneth Sutton, also of the Aero thermodynamics Branch for his continued support. This work is supported in part by the following grants: NASA Graduate Student Researchers Program Fellowship NGT-51005, NASA Langley Research Center Cooperative Agreement NCC1-140 with the Aerothermodynamics Branch of the Space Systems Division, and NASA Grant NAGW-1331 to the Mars Mission Research Center at North Carolina State University. Computer time was provided by the North Carolina Supercomputing Center and NASA Langley Research Center.